A Study of the Wave Interaction Between Light Beams Having Large Path Difference

摘要

The work has been directed toward an experiment to measure the velocity of light using a well regulated thermal light source such as a Mercury 198 isotope lamp and depending upon the random fluctuations of the source to substitute for the usual modulation (e.g. toothed wheel). In such an experiment the signal to noise problem is very severe and the major effort has been to consider possible ways of overcoming this difficulty. It was demonstrated that the beating between modes of a continuously operating gas laser serves to modulate the intensity and thus enables one to measure the velocity of light without any other modulating device. A new technique was devised and tested for measuring the variation in time of flight of electrons through a photomultiplier as a function of the cathode position from which they are emitted. (Author)